I own a foundation repair company, so I don’t get scared off by those problems.  

Just make sure to consult with a couple of septic contractors as well as the local health department or environmental services division of the city or county to make sure you have all permits and fees accounted for.

I don't want to scare them away and ruin the deal. 

it can be easier it seems to take advantage of some tax breaks if you have them, like owning your vehicle and even buying health insurance for employees if you get big enough. 

All the parents picking up the kids are talking about it and how scared everyone is.

People are too scared to invest when the economy is a disaster. 

What part of SC are you in?

No matter how many dollars Z is throwing at marketing, no one can buy off your reputation of THE go to person that buys and flips houses.Don't be scared of Zillow.

How do you seasoned investors find good deals on rental properties, and what are big red flags that scare you away from certain properties?

If they are paying the rent on time, and otherwise are not destroying the 'unit', I would leave them there and initiate a monthly extermination done by a licensed pest control company, and back charge the tenant for it.You can't change their lifestyle, but you can protect your property from becoming a health hazard.